Biomedical subjects

Peter Martus

Publications and source records attributed to Peter Martus.

At least 37 records · Page 2Linked to original sources

PubMed2005

Transformation and other factors of the peptide mass spectrometry pairwise peak-list comparison process.

BACKGROUND: Biological Mass Spectrometry is used to analyse peptides and proteins. A mass spectrum generates a list of measured mass to charge ratios and intensities of ionised peptides, which is called a peak-list. In order to classify the underlying amino acid sequence, the acquired spectra are usually compared with synthetic ones. Development of suitable methods of direct peak-list comparison may be advantageous for many applications. RESULTS: The pairwise peak-list comparison is a multistage process composed of matching of peaks embedded in two peak-lists, normalisation, scaling of peak intensities and dissimilarity measures. In our analysis, we focused on binary and intensity based measures. We have modified the measures in order to comprise the mass spectrometry specific properties of mass measurement accuracy and non-matching peaks. We compared the labelling of peak-list pairs, obtained using different factors of the pairwise peak-list comparison, as being the same or different to those determined by sequence database searches. In order to elucidate how these factors influence the peak-list comparison we adopted an analysis of variance type method with the partial area under the ROC curve as a dependent variable. CONCLUSION: The analysis of variance provides insight into the relevance of various factors influencing the outcome of the pairwise peak-list comparison. For large MS/MS and PMF data sets the outcome of ANOVA analysis was consistent, providing a strong indication that the results presented here might be valid for many various types of peptide mass measurements.

Algorithms↗

PubMed2005

Prognostic significance of tumor regression after preoperative chemoradiotherapy for rectal cancer.

PURPOSE: We assessed the impact of tumor regression grading (TRG) and its value in correlation to established prognostic factors in a cohort of rectal carcinoma patients treated by preoperative chemoradiotherapy (CRT). PATIENTS AND METHODS: TRG was evaluated on surgical specimens of 385 patients treated within the preoperative CRT arm of the CAO/ARO/AIO-94 trial: 50.4 Gy was delivered, fluorouracil was given in the first and fifth week, and surgery was performed 6 weeks thereafter. TRG was determined by the amount of viable tumor versus fibrosis, ranging from TRG 4 when no viable tumor cells were detected, to TRG 0 when fibrosis was completely absent. TRG 3 was defined as regression more than 50% with fibrosis outgrowing the tumor mass, TRG 2 was defined as regression less than 50%, and TRG 1 was defined basically as a morphologically unaltered tumor mass. We performed an initially unplanned, hypothesis-generating analysis with respect to the prognostic value of this TRG system. RESULTS: TRG 4, 3, 2, 1, 0 was found in 10.4%, 52.2%, 13.8%, 15.3%, and 8.3% of the resected specimens, respectively. Five-year disease-free survival (DFS) after CRT and curative resection was 86% for TRG 4, 75% for grouped TRG 2 + 3, and 63% for grouped TRG 0 + 1 (P = .006). On multivariate analysis, the pathologic T category and the nodal status after CRT were the most important independent prognostic factors for DFS. CONCLUSION: In this exploratory analysis, complete (TRG 4) and intermediate pathologic response (TRG 2 + 3) suggested improved DFS after preoperative CRT. TRG assessment should be implemented in pathologic evaluation and prospectively validated in further studies.

Adenocarcinoma↗

PubMed2005

Retrospective study of prognostic factors in non-Hodgkin lymphoma secondarily involving the central nervous system.

The aim of this retrospective single-center study was to analyze the clinical characteristics and outcome of non-Hodgkin lymphoma (NHL) patients with central nervous system (CNS) involvement and to identify prognostic factors for survival. We searched our hospital records for NHL patients diagnosed with CNS involvement from 1982 to 2004, and 43 patients were identified. The median age was 63 years (range 23-88) and the median Karnofsky performance status was 55% (range 10-90). Treatment of CNS lymphoma included intrathecal chemotherapy in 33 patients (77%), systemic chemotherapy in 25 (58%), and radiotherapy in 16 (37%). Twenty-six patients showed a CNS response. The median survival after CNS manifestation was 5 months (range 2 days-82.5+months). Nine patients achieved long-term survival. Low lactate dehydrogenase (LDH) at CNS manifestation and a CNS response to therapy were favorable independent prognostic factors for survival in multivariate analysis (p = 0.051 and p < 0.0005, respectively), whereas a young age at initial diagnosis, initial CNS involvement, an initially normal LDH, and high-dose chemotherapy for CNS involvement were significant in univariate analysis. In conclusion, long-term survival can be achieved in patients with secondary CNS lymphoma. LDH at CNS manifestation and a CNS response to therapy were significantly associated with survival.

Adult↗

PubMed2005

Predictive factors for visual acuity after intravitreal triamcinolone treatment for diabetic macular edema.

OBJECTIVE: To evaluate which factors influence maximum gain in best-corrected visual acuity after intravitreal injection of triamcinolone acetonide as treatment for diffuse diabetic macular edema. METHODS: This prospective clinical interventional study included 53 eyes with diffuse diabetic macular edema receiving an intravitreal injection of about 20 mg of triamcinolone. The mean +/- SD follow-up was 10.2 +/- 7.6 months. RESULTS: In a multiple linear regression analysis, maximum gain in best-corrected visual acuity after the intravitreal injection of triamcinolone was significantly (P < .001) and negatively correlated with an increased degree of macular ischemia and a higher preoperative visual acuity. Improvement in best-corrected visual acuity was significantly and positively correlated with increased degree of macular edema (P = .001). Change in best-corrected visual acuity after the intravitreal triamcinolone injection was statistically independent (P > .15) of age, sex, pseudophakia, and macula grid laser treatment before inclusion into the study. The results were comparable for gain in visual acuity at 6 months after the injection. CONCLUSION: Pronounced macular edema may have a positive impact, and marked macular ischemia and a high preoperative best-corrected visual acuity may have a negative impact, on an increase in best-corrected visual acuity after intravitreal triamcinolone injection in patients with diabetic macular edema.

Adult↗

PubMed2005

Predictive factors for progressive optic nerve damage in various types of chronic open-angle glaucoma.

PURPOSE: To evaluate whether various types of chronic open-angle glaucoma differ in predictive factors for progression of glaucomatous optic nerve damage. DESIGN: Observational cohort study. METHODS SETTING: Prospective observational clinical study. PATIENTS: 517 eyes of 300 Caucasian patients with chronic open-angle glaucoma with elevated intraocular pressure (primary open-angle glaucoma, n = 289; secondary open-angle glaucoma, n = 50) and with normal intraocular pressure (n = 178). OBSERVATION PROCEDURE: During follow-up (median: 49 months, 6 months-130 months), all patients underwent repeated evaluation of color stereo optic disk photographs and white-on-white visual field examination. MAIN OUTCOME MEASURES: Progression of glaucoma was defined as neuroretinal rim loss during the study period. RESULTS: For patients with elevated intraocular pressure, significantly predictive factors for eventual progression were older age, advanced perimetric damage, smaller neuroretinal rim, and larger area of beta zone of parapapillary atrophy. In contrast, in the normal intraocular pressure group, a significant predictive factor was presence of disk hemorrhages at baseline. Within the patients with elevated intraocular pressure, the primary open-angle glaucoma group and the secondary open-angle glaucoma group did not differ in predictive factors for progression of glaucoma. CONCLUSIONS: Open-angle glaucoma patients with normal intraocular pressure and open-angle glaucoma patients with elevated intraocular pressure differ in predictive factors for eventual progression of glaucomatous optic nerve damage. It may have clinical importance and may be helpful in the discussion of the pathogenesis of the glaucomas.

Adolescent↗

PubMed2005

The flavonoid phloretin suppresses stimulated expression of endothelial adhesion molecules and reduces activation of human platelets.

Atherosclerosis is a chronic inflammatory disease accompanied by the expression of endothelial adhesion molecules. Phloretin is a plant-derived phytochemical that is mainly present in apples. Because phloretin is reported to promote antioxidative activities, we investigated the effects of phloretin on cytokine-induced expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule-1 (E-selectin) in human umbilical vein endothelial cells (HUVECs). Phloretin prevented TNF-alpha-stimulated upregulation of VCAM-1, ICAM-1, and E-selectin expression in a concentration-dependent manner. To the same extent as for TNF-alpha, phloretin also inhibited IL-1beta-induced upregulation in expression of all 3 adhesion molecules. Inhibition of cytokine-induced adhesion molecule expression for VCAM-1, ICAM-1, and E-selectin was detected already at the level of mRNA. Preincubation with phloretin dose-dependently attenuated TNF-alpha-stimulated adhesion of monocytic THP-1 cells to HUVECs and human aortic endothelial cells. Phloretin did not affect TNF-alpha-stimulated activation of nuclear factor kappaB (NF-kappaB) but inhibited activation of interferon regulatory factor 1, a transcription factor involved in the regulation of endothelial cell adhesion molecule expression. In human platelets, phloretin diminished adenosine diphosphate (ADP) and thrombin receptor-activating peptide-stimulated expression of the activated form of the GPIIb/IIIa complex and reduced platelet aggregation stimulated by ADP. Thus phloretin may have beneficial effects in the onset and progression of cardiovascular diseases.

Blood Platelets↗

PubMed2005

Response to chemotherapy and treating institution predict survival in primary central nervous system lymphoma.

The majority of the available data on primary central nervous system lymphoma (PCNSL) derive from small unicentric or oligocentric studies. In this multicentre study, we evaluated the response, survival and toxicity in PCNSL patients after carmustine, methotrexate 1.5 g/m2, procarbazine and dexamethasone (BMPD) chemotherapy and searched for prognostic factors. Fifty-six patients received the BMPD protocol (dexamethasone was given only in course 1). The overall complete response rate to chemotherapy was 61% (34/56). Ten complete responders received whole-brain irradiation and 24 were not irradiated. Responders to chemotherapy had significantly longer median overall survival than non-responders (18.2 vs. 9.9 months, P = 0.02). Median survival was significantly longer at institutions accruing at least four patients than at those with fewer patients (31.5 vs. 9.5 months, P = 0.03).

Adult↗

PubMed2005

Central corneal thickness correlated with glaucoma damage and rate of progression.

PURPOSE: To evaluate whether the amount of glaucomatous optic nerve damage at presentation of the patient and the rate of progression of glaucoma during follow-up are related to central corneal thickness. METHODS: The prospective observational clinical study included 861 eyes of 454 white subjects (239 normal eyes of 121 subjects, 250 ocular hypertensive eyes of 118 patients, 372 eyes of 215 patients with chronic open-angle glaucoma). For 567 eyes (304 patients) with ocular hypertension or chronic open-angle glaucoma, follow-up examinations were performed, with a mean follow-up time of 62.7 +/- 33.2 months (median, 60.8; range, 6.2-124.9). All patients underwent qualitative and morphometric evaluation of color stereo optic disc photographs and white-on-white visual field examination. Central corneal thickness was measured by corneal pachymetry. RESULTS: Central corneal thickness correlated significantly (P < 0.001) and positively with the area of the neuroretinal rim and negatively with the loss of visual field. Development or progression of glaucomatous visual field defects detected in 119 (21.0%) eyes was statistically independent of central corneal thickness, in univariate (P = 0.99) and multivariate Cox regression analyses (P = 0.19). CONCLUSIONS: At the time of patient referral, the amount of glaucomatous optic nerve damage correlated significantly with a thin central cornea. Progression of glaucomatous optic nerve neuropathy was independent of central corneal thickness, suggesting that central corneal thickness may not play a major role in the pathogenesis of progressive glaucomatous optic nerve damage.

Adolescent↗

PubMed2004

Upregulation of myocardial estrogen receptors in human aortic stenosis.

BACKGROUND: Estrogen receptor (ER)-mediated effects have been associated with the modulation of myocardial hypertrophy in animal models and in humans, but ER expression in the human heart and its relation to hypertrophy-mediated gene expression have not yet been analyzed. We therefore investigated sex- and disease-dependent alterations of myocardial ER expression in human aortic stenosis together with the expression of hypertrophy-related genes. METHODS AND RESULTS: ER-alpha and -beta, calcineurin A-beta, and brain natriuretic peptide (BNP) mRNA were quantified by real-time polymerase chain reaction in left ventricular biopsies from patients with aortic valve stenosis (n=14) and control hearts with normal systolic function (n=17). ER protein was quantified by immunoblotting and visualized by immunofluorescence confocal microscopy. ER-alpha mRNA and protein were increased 2.6-fold (P=0.003) and 1.7-fold (P=0.026), respectively, in patients with aortic valve stenosis. Left ventricular ER-beta mRNA was increased 2.6-fold in patients with aortic valve stenosis (P<0.0001). ER-alpha and -beta were found in the cytoplasm and nuclei of human hearts. A strong inverse correlation exists between ER-beta and calcineurin A-beta mRNA in patients with aortic valve stenosis (r=-0.83, P=0.002) but not between ER-alpha or -beta and BNP mRNA. CONCLUSIONS: ER-alpha and -beta in the human heart are upregulated by myocardial pressure load.

Adrenergic beta-Antagonists↗

PubMed2004

Preoperative versus postoperative chemoradiotherapy for rectal cancer.

BACKGROUND: Postoperative chemoradiotherapy is the recommended standard therapy for patients with locally advanced rectal cancer. In recent years, encouraging results with preoperative radiotherapy have been reported. We compared preoperative chemoradiotherapy with postoperative chemoradiotherapy for locally advanced rectal cancer. METHODS: We randomly assigned patients with clinical stage T3 or T4 or node-positive disease to receive either preoperative or postoperative chemoradiotherapy. The preoperative treatment consisted of 5040 cGy delivered in fractions of 180 cGy per day, five days per week, and fluorouracil, given in a 120-hour continuous intravenous infusion at a dose of 1000 mg per square meter of body-surface area per day during the first and fifth weeks of radiotherapy. Surgery was performed six weeks after the completion of chemoradiotherapy. One month after surgery, four five-day cycles of fluorouracil (500 mg per square meter per day) were given. Chemoradiotherapy was identical in the postoperative-treatment group, except for the delivery of a boost of 540 cGy. The primary end point was overall survival. RESULTS: Four hundred twenty-one patients were randomly assigned to receive preoperative chemoradiotherapy and 402 patients to receive postoperative chemoradiotherapy. The overall five-year survival rates were 76 percent and 74 percent, respectively (P=0.80). The five-year cumulative incidence of local relapse was 6 percent for patients assigned to preoperative chemoradiotherapy and 13 percent in the postoperative-treatment group (P=0.006). Grade 3 or 4 acute toxic effects occurred in 27 percent of the patients in the preoperative-treatment group, as compared with 40 percent of the patients in the postoperative-treatment group (P=0.001); the corresponding rates of long-term toxic effects were 14 percent and 24 percent, respectively (P=0.01). CONCLUSIONS: Preoperative chemoradiotherapy, as compared with postoperative chemoradiotherapy, improved local control and was associated with reduced toxicity but did not improve overall survival.

Adult↗

PubMed2004

GEE approaches to marginal regression models for medical diagnostic tests.

The evaluation of a new medical diagnostic test may focus on two different scientific questions: (1). The new test may replace an existing one because of lower cost or higher validity. A related question would be the selection of the 'best' test(s) from a bundle of new or established measurements. (2). The new test may be used supplementary to other new or established procedures. In a recent publication, Leisenring and co-workers (Stat Med 1997; 16:1263-1281) developed a general marginal regression model for comparisons of diagnostic tests focussing on question (1). i.e. on the selection of the 'best' procedure. They applied the GEE approach of Liang and Zeger (Biometrika 1987; 73:13-22) to adjust for the correlation of data as a nuisance parameter. Using the general framework provided by Leisenring et al., we extend their approach and apply the GEE methodology to question (2). i.e. to the investigation of which of several diagnostic tests should be used supplementary to each other. We analyse data from a longitudinal study concerning pathogenesis, diagnosis and long-term course of the eye disease glaucoma. We find a dependence of the correlation structure of several diagnostic measurements on the severity of the disease. This result may be useful in clinical applications as regards the selection of subsets of diagnostic measurements in individual diagnostic processes but also in investigations concerning the relationship of the pathogenic process and the rationales of the different diagnostic procedures.

Biometry↗

PubMed2004

Proton therapy of uveal melanomas in Berlin. 5 years of experience at the Hahn-Meitner Institute.

BACKGROUND AND PURPOSE: In June 1998, proton-beam therapy of ocular tumors started at the Hahn-Meitner Institute Berlin, Germany. The purpose of the present study is to evaluate treatment outcome for uveal melanomas. PATIENTS AND METHODS: 245 consecutive patients with primary melanoma of the uvea were treated from June 1998 to April 2003 with a 68-MeV proton beam. In 96.2% of all patients, a uniform fractionation scheme was applied: single dose 15 CGE (cobalt gray equivalent), total dose 60 CGE on 4 consecutive days. Follow-up is available in 229 patients. RESULTS: At the time of median follow-up (18.4 months), local control is 96.4% and 95.5% at 3 years. Eye retention rate is 92.6% at 20 months (median follow-up) and 87.5% at 3 years. CONCLUSION: Proton-beam irradiation of uveal melanomas at the Hahn-Meitner Institute after the first 5 years of its initiation reveals local tumor control and eye retention rates in the range of other centers with larger experience. Delivering high treatment quality in hadron therapy from the beginning has been achieved.

Adolescent↗

PubMed2004

Independent prognostic factors for distant metastases and survival in patients with primary uveal melanoma.

Adjuvant treatment strategies in uveal melanoma require determination of prognostic factors. Patients, who received primary therapy in 1994 and 1995 at our institution, were analysed. Of 271 patients 85% and 71% were available for follow up of 4 and 5 years. Forty three patients (15.9%) developed metastases. Kaplan-Meier analysis revealed a 5-year progression free survival (PFS) of 79% for the whole patient cohort. Extraocular tumor growth (EOG), ciliary body involvement or a largest tumor diameter (LTD) >14 mm were associated with a significantly lower 5-year PFS of 28%, 61.4% or 67.6%. In multivariate analysis time to progression was significantly associated with ciliary body involvement and LTD, and survival was associated with ciliary body involvement. Ciliary body involvement profoundly increased the risk for metastases (hazard ratio 6.9, P<0.001) within the first 3 years. This study determined patients with ciliary body involvement to be candidates for future adjuvant therapeutic interventions.

Adolescent↗

PubMed2004

Comparison of 6-month results of implantation of the 1CU accommodative intraocular lens with conventional intraocular lenses.

OBJECTIVE: To evaluate the clinical results of implantation of the new 1CU accommodative intraocular lens (IOL) in cataract patients and to compare results with those of conventional IOLs. DESIGN: Nonrandomized comparative trial. PARTICIPANTS: Twenty eyes of 20 patients (mean age = 65.8+/-13.3 years) in the 1CU group and 20 eyes of 20 patients (mean age = 67.4+/-11.6 years) in the control group. METHODS: All patients underwent phacoemulsification and IOL implantation. The 1CU accommodative lens was used in 20 eyes, and conventional IOLs (polymethyl methacrylate, hydrophilic or hydrophobic acrylate) were used in the control group. Patients were observed prospectively, and 6-month data were analyzed. MAIN OUTCOME MEASURES: Accommodative ranges determined by 3 different methods (near point, defocusing, and retinoscopy). Secondary outcome measures were (1) increase of anterior chamber depth after topical application of 1% cyclopentolate eyedrops and (2) distance-corrected near visual acuity with Birkhäuser reading charts at 35 cm. RESULTS: We observed a higher accommodative range with all 3 methods (mean = 1.83+/-0.49 vs. 1.16+/-0.27 diopters [D] [near point], 1.85+/-0.43 vs. 0.64+/-0.21 D [defocusing], and 0.98+/-0.55 vs. 0.17+/-0.22 D [retinoscopy]), a larger increase of anterior chamber depth after cyclopentolate eyedrops (mean = 0.42+/-0.18 vs. 0.11+/-0.06 mm), and better distance-corrected near visual acuity (median = 0.4 vs. 0.2) in the 1CU group relative to the control group. All differences between the 2 groups were statistically highly significant (P<0.001). CONCLUSIONS: In the present study, the 1CU accommodative IOL showed increased accommodative range and better near visual acuity than a control group with conventional IOLs. Further research is necessary to confirm these results in masked, randomized, prospective studies and to confirm further the accommodative power of this group of new IOLs.

Accommodation, Ocular↗

PubMed2004

Sliding wear of 19 commercially available composites and compomers.

OBJECTIVES: The aim of this study was to determine the influence of particle size, particle material and morphology on the sliding wear of 19 light curing, commercially available composites (Durafill VS, Metafil CX, Heliomolar RO, Solitaire, Arabesk, Artglass, Charisma F, Pertac II, Charisma, Degufill Ultra, TPH Spectrum, Z100, Tetric classic, Pertac Hybrid, Estilux Hybrid, Dyract AP, Compoglass F, Compoglass and Hytac). METHODS: The materials were applied to an aluminum sample holder (7.5 mm diameter, 2 mm depth) in one layer and polymerized in a Dentacolor XS light curing unit for 180 s. The surface was ground flat (#1000) to remove any matrix rich surface layer. Then samples were stored in Ringer's solution for 24 h at 37 degrees C. Occlusal contact wear was simulated in a sliding wear tester (Munich Artificial Mouth). Eight specimens of each material were tested in a pin-on-block design with oscillating sliding of a Degussit antagonist (5 mm diameter) at a vertical load of 50 N. The horizontal excursion of the antagonist was 8 mm. Wear was quantified by a replica technique every 6000, 10,000, 30,000 and 50,000 cycles using a 3D-laser scanner. The materials were compared by their mean wear after 50,000 cycles. Comparisons of different composites and compomers were performed using analysis of variance and t-tests including the Bonferroni correction. RESULTS: The microfiller composites (Durafill VS, Metafil CX, Heliomolar RO) revealed the lowest, and the compomers (Dyract AP, Compoglass F, Compoglass and Hytac) showed the highest contact wear (p < 0.05). The wear of the hybrid composite (Estilux Hybrid) and the micro hybrid composites (Solitaire, Arabesk, Artglass, Charisma F, Pertac II, Charisma, Degufill Ultra, TPH Spectrum, Z100, Tetric classic, Pertac Hybrid) was higher than that of the microfiller composites (p < 0.05). The results showed additional significant differences within the three groups of composites. The coefficient of determination between loss of height and maximum particle size was r2 = 0.41. SIGNIFICANCE: Both particle size and morphology have a high influence on the wear properties concerning the two-body wear in the occlusal contact area.

Compomers↗

PubMed2004

The effect of variable CYP3A5 expression on cyclosporine dosing, blood pressure and long-term graft survival in renal transplant patients.

OBJECTIVE: Cyclosporine is extensively metabolized by cytochrome-P450 3A (CYP3A) enzymes in the liver and intestine including the CYP3A5 isoenzyme. CYP3A5 is also expressed in the kidney and has been implicated in blood pressure regulation. Appreciable expression of CYP3A5 occurs in carriers of the CYP3A5*1 allele, while the CYP3A5*3 allele is associated with low expression. We tested whether the presence of the CYP3A5*1 allele in renal transplant recipients and in donor kidneys influences cyclosporine dose requirements, blood pressure and long-term graft survival in renal transplant patients during chronic treatment with a cyclosporine-based immunosuppressive regimen. METHODS: We studied 399 Caucasian patients from our single-center registry with stable graft function for more than 10 weeks after transplantation. The genotypes for CYP3A5*1/*3 were determined by a TaqMan PCR method. Cyclosporine dose requirements, blood pressure and graft survival were analyzed in relation to the presence or absence of the CYP3A5*1 allele in recipients and donor kidneys. RESULTS: The CYP3A5*1 allele was found in 15.5% of the recipients and in 11.8% of the donor kidneys. The recipient CYP3A5*1 allele had no effect on cyclosporine dose and blood concentrations at trough with and without dose-adjustment. Blood pressure, number of antihypertensive compounds used for treatment and graft survival evaluated by Kaplan-Meier curves and Cox regression analysis were also not affected by the CYP3A5*1 allele either in recipients or donor kidneys. CONCLUSIONS: Cyclosporine dose requirements, blood pressure and long-term renal graft survival are not influenced by the CYP3A5*1 allele in Caucasian patients.

Adult↗

PubMed2004

The optic disc hemifield test.

PURPOSE: To evaluate whether an optic disc hemifield test comparing the superior half of the optic disc with the inferior disc half is useful for glaucoma diagnosis. METHODS: The clinical observational study included 1268 patients with primary or secondary open-angle glaucoma and 649 normal subjects. The glaucoma group was divided into 1118 patients with glaucomatous visual field defects ("perimetric glaucoma"), and 150 patients with optic nerve head changes and normal visual fields ("preperimetric glaucoma"). Color stereo optic disc photographs were morphometrically evaluated. The optic disc area was divided into four sectors: temporal horizontal (60 degrees), superotemporal (90 degrees), inferotemporal (90 degrees), and nasal (120 degrees). Area and width of the neuroretinal rim were measured, and the ratio of superotemporal-to-inferotemporal rim area, the ratio of superior (12 o'clock)-to-inferior (6 o'clock) rim width, the difference of inferotemporal minus superotemporal rim area, and the difference of inferior rim width minus superior rim width were calculated. RESULTS: For the differentiation between the normal group and the whole glaucoma group, and for the differentiation between the normal group and the preperimetric glaucoma group, respectively, areas under the ROC curves were significantly smaller for the parameters of the optic disc hemifield test (superior-to-inferior rim width ratio: 0.448 and 0.412, respectively; and superotemporal-to-inferotemporal rim area ratio: 0.395 and 0.434, respectively) than for any other rim parameter tested such as inferotemporal rim area (0.827 and 0.745, reps.), total rim area (0.814 and 0.741, respectively), and superotemporal rim area (0.781 and 0.705, respectively). DISCUSSION: An optic disc hemifield test with the parameters superior-to-inferior rim width ratio and superotemporal-to-inferotemporal rim area ratio is not markedly helpful for the morphometric diagnosis of glaucomatous optic nerve damage, either in the preperimetric stage or in the perimetric stage of the disease.

Diagnostic Techniques, Ophthalmological↗

PubMed2004

ADP induced platelet degranulation in healthy individuals is reduced by clopidogrel after pretreatment with atorvastatin.

Statins inhibit platelet reactivity and reduce blood thrombogenicity. The effectiveness of clopidogrel in inhibiting platelet reactivity was suggested to be reduced in the presence of atorvastatin due to shared enzymes in metabolism. Healthy individuals, 17 pretreated with atorvastatin (20 mg/d for 3 days) and 17 without pretreatment, as well as 15 patients with stable coronary artery disease (CAD) and concurrent atorvastatin therapy were started on clopidogrel (loading dose 300 mg, then 75 mg/d). P-selectin on platelet surface after stimulation with ADP or Thrombin Receptor Activating Peptide (TRAP) was flow cytometrically measured before and during clopidogrel administration. Whole blood platelet agglutination was tested by a platelet function assay.TRAP and - in trend - ADP induced p-selectin exposure was reduced by the atorvastatin pretreatment before clopidogrel was added. Combining clopidogrel with atorvastatin in the healthy individuals led to a further reduction in ADP-induced platelet p-selectin exposure. Clopidogrel also reduced platelet reactivity in CAD patients with concurrent atorvastatin medication. We conclude that pretreatment with atorvastatin reduces platelet reactivity before administration of clopidgrel. No drug interaction was seen, however, platelet inhibitory effects were observed during the treatment with clopidogrel and atorvastatin.

Adenosine Diphosphate↗